Diagnostic evaluation of a

symptomatic cerebrovascular

accident in a neonate with

focal convulsions

SWISS SOCIETY OF NEONATOLOGY

July 2013

2

Anderson S, Rimensberger P, Service de Néonatologie et des

Soins Intensifs Pédiatriques, Département de l’Enfant et de

l’Adolescent, Hôpitaux Universitaires de Genève

© Swiss Society of Neonatology, Thomas M Berger, Webmaster

3

Focal neonatal convulsions are usually related to peri-

natal asphyxia with hypoxic ischemic encephalopathy

or cerebrovascular accidents which include hemor-

rhagic lesions (including hemorrhagic periventricular

leukomalacia), arterial ischemic stroke or sinus venous

thrombosis.

With an estimated incidence of 1 in 4’000 delive-

ries, ischemic infarction is a rare cause of neurologi-

cal symp toms in the neonatal period (1). Occlusion of

a major cerebral artery can be due to an embolic or

thrombotic event. Clinically, patients typically present

with focal seizures and no altered consciousness bet-

ween the episodes. Standard techniques such as ce-

rebral ultrasound, electroencephalograms (EEGs) and

magnetic resonance imaging (MRI) aid in early dia-

gnosis (2). Additional information from cerebral blood

flow velocity measurements using transcranial Doppler

examinations might be useful for early differentiati-

on between perinatal arterial stroke and other types

of cerebral vascular lesions. Thus, diagnostic MRI may

not be required as an emergency examination.

INTRODUCTION

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CASE REPORT This male patient was born by Cesarean section be-

cause of failure of labor progression at 37 weeks and

3 days of gestation with a birth weight of 3050 g.

Neonatal adaption was normal with Apgar scores of

9, 10, and 10 at 1, 5, and 10 minutes, respectively.

Family history revealed no convulsive, hematologic or

neurologic disorders.

On day 3 of life, there were three episodes of convul-

sions, which were initially focal with cloni of the right

arm and eye deviation to the upper right, then gene-

ralized secondarily with symmetric cloni and nystag-

mus. Each episode lasted for 2-3 minutes, and was

accompanied by tachycardia and falling oxygen satu-

rations. Adequate behavior was observed between the

episodes. Serum concentrations of glucose and elec-

trolytes were normal. After the third episode, pheno-

barbital treatment was started with a loading dose of

10 mg/kg followed by a maintenance dose of 5 mg/

kg/d. No more clinical episodes of convulsion were re-

corded thereafter.

Initial laboratory analyses of blood and cerebrospinal

fluid showed normal values for electrolytes, ammoni-

um, pyruvate, coagulation factors as well as infectious

parameters. Common metabolic disorders were exclu-

ded with normal newborn screening results (Guthrie

test).

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Within 30 min after admission to NICU, cerebral ar-

tery flow velocity (CAFV) measured with transcranial

Doppler ultrasound of the left middle cerebral artery

(MCA) was diminished compared to the right MCA.

Peak systolic blood flow velocities were more than

25% higher (45 cm/s vs. 35 cm/s), and the end-diasto-

lic blood flow velocities were more than 60% (20 cm/s

vs. 12 cm/s) higher in the right MCA when compared

to the left MCA. There were also marked differences

in the resistance index values between the right and

left MCA (0.55 vs. 0.66) (Fig. 1). In addition, thalamic

hyperechogenic signals were detected on the initial

cerebral ultrasound.

Magnetic resonance imaging (MRI) 2 days after the

convulsions showed extensive acute ischemic lesions

in the left temporal lobe, as well as involvement of the

left thalamus, the posterior part of the left internal

capsula, and the left peduncle of the splenium of the

corpus callosum. No thrombus could be detected on

MR angiography (Fig. 2-4).

The EEG on day 3 of life showed no abnormalities. Fur-

ther laboratory analysis did not reveal an underlying

coagulation disorder (antithrombin III, factors II and V,

protein C and S). Maternal anticardiolipin antibodies,

lupus anticoagulants, ac-ß2-microglobulin could not

be detected.

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Fig. 1

Cerebral artery flow velocity (CAFV) of the middle

cerebral arteries (MCA): The peak systolic blood flow

velocities were at 35 cm/s and 45 cm/s, the end-

diastolic blood flow velocities at 12 cm/s and 20 cm/s

in the left and right MCA, respectively. The resistance

indices were 0.66 (left) and 0.55 (right).

left MCA

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right MCA

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Fig. 2

PWI (perfusion weighted imaging) sequence on day 4,

48h after the convulsions, revealing diminished

perfusion of the left temporal lobe.

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Neonatal seizures, one of the most common clinical

manifestations of central nervous system disorders

in the neonatal period, with a reported incidence of

1.5–14/1000 live births, can be either symptomatic or

idiopathic. Perinatal hypoxic ischemic insults (reported

seizure incidence of 40%-60%) and cerebrovascular

accidents (reported seizure incidence of 8%-20%),

birth trauma, perinatally acquired infections and me-

tabolic disturbances can be the cause of early sym-

ptomatic neonatal seizures. Furthermore, although

rare, congenital brain anomalies, inborn errors of me-

tabolism and genetic disorders can lead to neonatal

seizures (3). Cerebrovascular accidents can be divided

into either non-hemorrhagic arterial ischemic strokes,

or hemorrhagic insults. The latter are often related

to sinus venous thrombosis (SVT). Perinatal arterial

ischemic stroke is the second most common under-

lying etio logy of neonatal seizures in the full-term

newborn. The prognosis of arterial ischemic stroke is

generally better than of SVT.

Most cases of infants with neonatal cerebral infarction

present with focal and clonic convulsions, few present

with generalized and clonic, or even subtle seizures.

The onset of seizure activity is between 12 and 76

hours after birth. Infants tend to be alert and respon-

sive between episodes and are not encephalopathic.

Focal convulsions are to be evaluated in their perinatal

context. As a first step, in addition to standard labora-

tory tests to exclude possible metabolic causes, a

DISCUSSION

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Fig. 3

DWI (diffusion weighted imaging) sequences on day 4,

48h after the convulsions, revealing ischemic lesions of

the left temporal lobe.

11

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Fig. 5

ADC (apparent diffusion coefficient) sequence on day 4,

48h after the convulsions, revealing ischemic lesions of

the left temporal lobe.

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detailed neurological and clinical evaluation of the ne-

onate between the episodes of convulsions is crucial.

With hemorrhagic lesions (including the hemorrhagic

PVL in preterm infants) patients show often an alte-

red level of consciousness, whereas patients with an

arterial ischemic stroke often display normal interic tal

behavior. Patients with SVT present with apneas (18%)

altered consciousness (2%), agitation (6%) or sepsis-

like symptoms (5%) (4).

Therapy of perinatal ischemic stroke is supportive

(5). SVT in the perinatal period is often associated

with hemorrhagic lesions (reported in 48-79% of the

cases). Nevertheless, anticoagulation with low mole-

cular-weight heparin has been proven to be safe (6)

and several case reports have documented successful

thrombolytic therapy. Therefore, early anticoagulation

and/or thrombolysis may have to be considered rapid-

ly. However, whether such treatment leads to a better

short- and long-term outcomes is unclear.

Cerebral ultrasound with high frequency transducers

enables examinations of high-risk neonates at the bed-

side. However, ischemic cerebral insults can be difficu-

lt to detect (7). Transcranial Doppler ultrasound is a

flexible, accessible, routinely used tool for the assess-

ment of several vascular pathologies (ie. vasospasm,

stenosis etc.) in the adult intensive care setting. In

the neonatal unit, transcranial Doppler ultrasound is

14

still used only rarely. Fukuda et al. (8), using this tech-

nique, described lower CAFVs in all cerebral arteries

of neonates who went on to develop PVL when com-

pared with control infants; this difference was found

from day 0 onwards. In another study, Basu et al. (9)

demonstrated higher CAFVs in the MCA in septic neo-

nates with high complication and mortality rates. They

consider the assessment of CAFVs early after birth as

an adjunct bedside, non-invasive investigation, which

may have immediate diagnostic and prognostic impli-

cations. Several case reports have described an asym-

metry of CAFV and RI measurements in the MCA in

neonates with cerebral infarcts (10-12). Finally, in a re-

cent study, color Doppler ultrasound has been shown

to be highly specific for ruling out SVT and therefore

being useful as part of a clinical-laboratory-imaging

algorithm (13).

Magnetic resonance imaging (MRI) has been

established as the imaging modality of choice for the

detection and evaluation of ischemic brain injury in

adults, because of its high sensitivity and specificity. In

the early phase of cerebral infarction of neonates, se-

veral reports have revealed the importance of diffusi-

on-weighted imaging (DWI) MRI to detect focal ische-

mic brain injury in neonates (14, 15). This sequence

can be used with high sensitivity during the first 2

days after a stroke. It has to be recognized that DWI

alterations in do not persist for more than one week.

After 5 days, diagnosis relies mainly on T2-weighted

images (16).

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webmaster@neonet.ch

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